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Doctors Medicines MCQs Q&A

  1. 71

  2. 31
  3. 91
  4. 81
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1 Answers

Option 4 : 81

Given:

Total number of students = 75

Girls are 20% of total students

The average marks of the whole class = 74.6

The average marks of boys = 73

Formula used:

Total marks students = Average marks students × Number of students

Calculation:

The number of girls = (20%) × 75 = 15

⇒ Number of boys = 60

Total marks students = Average marks students × Number of students

⇒ Total marks of all students = 75 × 74.6 = 5595

⇒ Total marks of boys = 73 × 60 = 4380

⇒ Total marks of girls = 15 × Average marks of girls

Total marks of all students = Total marks of boys + Total marks of girls

⇒ 5595 = 4380 + (15 × Average marks of girls)

⇒ 1215 = (15 × Average marks of girls)

⇒ Average marks of girls = 81

∴ The average marks of girls are 81 

⇒ x = 74.6 + 4 × 1.6 = 81

∴ The average marks of girls are 81

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Related Questions

Questions below followed by three quantities. Find the relationship between them. Quantity I: In a class with a certain number of students if a teacher weighing 78 kg is added, then average weight of class is increased by 2 kg. If one more teacher weighing 66 kg is added, then the average weight of the class increases by 3.5 kg over the original average. What is the original average weight (in kg) of the class Quantity II: The average age of 16 students and their teacher's age is 16 years. If the teacher's age is excluded, the average reduces by 2. What is the teacher's age Quantity III: Average weight of three friends A, B and C is 46 kg. Another person D joins the group and now the average is 45 kg. If another person E whose weight is 6 kg more than D, joins the group replacing A, then average weight of B, C, D and E becomes 47 kg. What is the weight of A (in kg)?
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